A known image reading apparatus includes a base member, a platen, a movable member, a reading unit, and a wiring cable.
The base member is a box shape whose upper face is open. The base member includes a bottom wall surface and a peripheral wall protruding upward from the bottom wall surface to define an accommodation area thereinside. The platen is supported by an upper end of the peripheral wall. The platen faces the bottom wall surface with a distance therebetween and covers the accommodation area. The movable member reciprocates from one end of the accommodation area to its opposite end in a scanning direction. The reading unit is supported by the movable member to face the platen in the accommodation area. The wiring cable has flexibility. A portion of the wiring cable is fixed to the bottom wall surface in the accommodation area. An end of the wiring cable is connected to the reading unit. The peripheral wall includes a side wall extending in the scanning direction.
The wiring cable includes a first extending portion, a curve portion, and a second extending portion. The first extending portion extends along the bottom wall surface from the portion of the wiring cable fixed to the bottom wall surface toward the opposite end of the accommodation area in the scanning direction. The curve portion is continued from the first extending portion. The curve portion curves to approach the platen and turns to face the base end. The second extending portion is continued from the curve portion and extends toward the base end along the platen.
In the image reading apparatus, the movable member reciprocates in the scanning direction. The reading unit moves together with the movable member and reads an image on a medium placed on the platen. At this time, the curve portion of the wiring cable reciprocates in the scanning direction in association with the reciprocating movement of the movable member. In association with the movement of the curve portion, one of the first extending portion and the second extending portion becomes longer and the other one of the first extending portion and the second extending portion becomes shorter. Thus, the wiring cable follows the reciprocating movement of the movable member and does not get in the way of image reading by the reading unit in the image reading apparatus.
In the known image reading apparatus, if the wiring cable is away from the side wall in a width direction perpendicular to the scanning direction, the size of the image reading apparatus is increased.
If the position of the wiring cable is moved closer to the side wall to reduce the size of the image reading apparatus, edges of the first extending portion, the curve portion and the second extending portion in the width direction are brought closer to the side wall. Accordingly, the first extending portion, the curve portion, and the second extending portion may readily contact the side wall. Dust (or particles) may be produced as a result of the wiring cable rubbing against the side wall. For example, particles of the side wall may be generated due to wear of the side wall over time. The dust may lead to reduction in an image reading quality as the dust moves closer to the reading unit. For example, dust may accumulate on the platen glass causing a reduction in image reading quality. In addition, as the side wall contacts the wiring cable, vibrations are caused in the wiring cable and side wall. Further, the vibrations may be transmitted to the movable member and the reading unit, leading to the reduction in an image reading quality. For example, vibrations may affect the movement of the movable member along its guide member if the guide member and/or movable member are vibrating.